Medical tele-robotic system with a master remote station with an arbitrator

ABSTRACT

A robotic system that includes a mobile robot linked to a plurality of remote stations. One of the remote stations includes an arbitrator that controls access to the robot. Each remote station may be assigned a priority that is used by the arbitrator to determine which station has access to the robot. The arbitrator may include notification and call back mechanisms for sending messages relating to an access request and a granting of access for a remote station.

REFERENCE TO CROSS-RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.10/206,457 filed on Jul. 25, 2002, pending, and claims priority toProvisional Application No. 60/449,762 filed on Feb. 24, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject matter disclosed generally relates to the field of robotics.

2. Background Information

There is a growing need to provide remote health care to patients thathave a variety of ailments ranging from Alzheimers to stress disorders.To minimize costs it is desirable to provide home care for suchpatients. Home care typically requires a periodic visit by a health careprovider such as a nurse or some type of assistant. Due to financialand/or staffing issues the health care provider may not be there whenthe patient needs some type of assistance. Additionally, existing staffmust be continuously trained, which can create a burden on trainingpersonnel. It would be desirable to provide a system that would allow ahealth care provider to remotely care for a patient without beingphysically present.

Robots have been used in a variety of applications ranging from remotecontrol of hazardous material to assisting in the performance ofsurgery. For example, U.S. Pat. No. 5,762,458 issued to Wang et al.discloses a system that allows a surgeon to perform minimally invasivemedical procedures through the use of robotically controlledinstruments. One of the robotic arms in the Wang system moves anendoscope which has a camera that allows a surgeon to view a surgicalarea of a patient.

Tele-robots such as hazardous waste handlers and bomb detectors maycontain a camera that allows the operator to view the remote site.Canadian Pat. No. 2289697 issued to Treviranus, et al. discloses ateleconferencing platform that has both a camera and a monitor. Theplatform includes mechanisms to both pivot and raise the camera andmonitor. The teleconferencing platform disclosed in the Canadian patentis stationary and cannot move about a building.

Publication Application No. US-2003-0050233-A1 discloses a remoterobotic system wherein a plurality of remote stations can control aplurality of robotic arms used to perform a minimally invasive medicalprocedure. Each remote station can receive a video image provided by theendoscope inserted into the patient. The remote stations are linked tothe robotic system by a dedicated communication link.

BRIEF SUMMARY OF THE INVENTION

A robotic system that includes a mobile robot coupled to a first remotestation and a second remote station. The second remote station includesan arbitrator that controls access to the robot. The robot includes acamera and a monitor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a robotic system;

FIG. 2 is a schematic of an electrical system of a robot;

FIG. 3 is a further schematic of the electrical system of the robot;

FIG. 4 is side view of the robot;

FIG. 5 is a top perspective view of a holonomic platform of the robot;

FIG. 6 is a side perspective view of a roller assembly of the holonomicplatform;

FIG. 7 is a bottom perspective view showing a pedestal assembly of therobot;

FIG. 8 is a sectional view showing an actuator of the pedestal assembly;

FIG. 9 is a schematic of a robotic system wherein multiple remotestations are coupled to the robot;

FIG. 10 is a flowchart showing an arbitration scheme for allowing accessto the robot;

FIG. 11 is a side view of a robot head.

DETAILED DESCRIPTION

Disclosed is a robotic system that includes a mobile robot linked to aplurality of remote stations. One of the remote stations includes anarbitrator that controls access to the robot. Each remote station may beassigned a priority that is used by the arbitrator to determine whichstation has access to the robot. The arbitrator may include notificationand call back mechanisms for sending messages relating to an accessrequest and a granting of access for a remote station.

Referring to the drawings more particularly by reference numbers, FIG. 1shows a robotic system 10. The robotic system 10 includes a robot 12, abase station 14 and a plurality of remote control stations 16. Eachremote control station 16 may be coupled to the base station 14 througha network 18. By way of example, the network 18 may be either a packetswitched network such as the Internet, or a circuit switched networksuch has a Public Switched Telephone Network (PSTN) or other broadbandsystem. The base station 14 may be coupled to the network 18 by a modem20 or other broadband network interface device.

Each remote control station 16 may include a computer 22 that has amonitor 24, a camera 26, a microphone 28 and a speaker 30. The computer22 may also contain an input device 32 such as a joystick or a mouse.Each control station 16 is typically located in a place that is remotefrom the robot 12. Although only one robot 12 is shown, it is to beunderstood that the system 10 may have a plurality of robots 12. Ingeneral any number of robots 12 may be controlled by any number ofremote stations. For example, one remote station 16 may be coupled to aplurality of robots 12, or one robot 12 may be coupled to a plurality ofremote stations 16.

The robot 12 includes a movement platform 34 that is attached to a robothousing 36. Also attached to the robot housing 36 are a camera 38, amonitor 40, a microphone(s) 42 and a speaker 44. The microphone 42 andspeaker 30 may create a stereophonic sound. The robot 12 may also havean antenna 45 that is wirelessly coupled to an antenna 46 of the basestation 14. The system 10 allows a user at the remote control station 16to move the robot 12 through the input device 32. The robot camera 38 iscoupled to the remote monitor 24 so that a user at the remote station 16can view a patient. Likewise, the robot monitor 40 is coupled to theremote camera 26 so that the patient can view the user. The microphones28 and 42, and speakers 30 and 44, allow for audible communicationbetween the patient and the user. The robot 12 may further have a handle48 that can be rotated to a down position which allows someone tomanually push or pull the robot 12.

Each remote station computer 22 may operate Microsoft OS software andWINDOWS XP or other operating systems such as LINUX. The remote computer22 may also operate a video driver, a camera driver, an audio driver anda joystick driver. The video images may be transmitted and received withcompression software such as MPEG CODEC.

FIGS. 2 and 3 show an embodiment of the robot 12. The robot 12 mayinclude a high level control system 50 and a low level control system52. The high level control system 50 may include a processor 54 that isconnected to a bus 56. The bus is coupled to the camera 38 by aninput/output (I/O) port 58, and to the monitor 40 by a serial outputport 60 and a VGA driver 62. The monitor 40 may include a touchscreenfunction that allows the patient to enter input by touching the monitorscreen.

The speaker 44 is coupled to the bus 56 by a digital to analog converter64. The microphone 42 is coupled to the bus 56 by an analog to digitalconverter 66. The high level controller 50 may also contain randomaccess memory (RAM) device 68, a non-volatile RAM device 70 and a massstorage device 72 that are all coupled to the bus 62. The mass storagedevice 72 may contain medical files of the patient that can be accessedby the user at the remote control station 16. For example, the massstorage device 72 may contain a picture of the patient. The user,particularly a health care provider, can recall the old picture and makea side by side comparison on the monitor 24 with a present video imageof the patient provided by the camera 38. The robot antennae 45 may becoupled to a wireless transceiver 74. By way of example, the transceiver74 may transmit and receive information in accordance with IEEE 802.11b.

The controller 54 may operate with a LINUX OS operating system. Thecontroller 54 may also operate MS WINDOWS along with video, camera andaudio drivers for communication with the remote control station 16.Video information may be transceived using MPEG CODEC compressiontechniques. The software may allow the user to send e-mail to thepatient and vice versa, or allow the patient to access the Internet. Ingeneral the high level controller 50 operates to control thecommunication between the robot 12 and the remote control station 16.

The high level controller 50 may be linked to the low level controller52 by serial ports 76 and 78. The low level controller 52 includes aprocessor 80 that is coupled to a RAM device 82 and non-volatile RAMdevice 84 by a bus 86. The robot 12 contains a plurality of motors 88and motor encoders 90. The encoders 90 provide feedback informationregarding the output of the motors 88. The motors 88 can be coupled tothe bus 86 by a digital to analog converter 92 and a driver amplifier94. The encoders 90 can be coupled to the bus 86 by a decoder 96. Therobot 12 also has a number of proximity sensors 98 (see also FIG. 1).The position sensors 98 can be coupled to the bus 86 by a signalconditioning circuit 100 and an analog to digital converter 102.

The low level controller 52 runs software routines that mechanicallyactuate the robot 12. For example, the low level controller 52 providesinstructions to actuate the movement platform to move the robot 12. Thelow level controller 52 may receive movement instructions from the highlevel controller 50. The movement instructions may be received asmovement commands from the remote control station. Although twocontrollers are shown, it is to be understood that the robot 12 may haveone controller controlling the high and low level functions.

The various electrical devices of the robot 12 may be powered by abattery(ies) 104. The battery 104 may be recharged by a batteryrecharger station 106 (see also FIG. 1). The low level controller 52 mayinclude a battery control circuit 108 that senses the power level of thebattery 104. The low level controller 52 can sense when the power fallsbelow a threshold and then send a message to the high level controller50. The high level controller 50 may include a power management softwareroutine that causes the robot 12 to move so that the battery 104 iscoupled to the recharger 106 when the battery power falls below athreshold value. Alternatively, the user can direct the robot 12 to thebattery recharger 106. Additionally, the battery 104 may be replaced orthe robot 12 may be coupled to a wall power outlet by an electrical cord(not shown).

FIG. 4 shows an embodiment of the robot 12. The robot 12 may include aholonomic platform 110 that is attached to a robot housing 112. Theholonomic platform 110 provides three degrees of freedom to allow therobot 12 to move in any direction.

The robot 12 may have an pedestal assembly 114 that supports the camera38 and the monitor 40. The pedestal assembly 114 may have two degrees offreedom so that the camera 26 and monitor 24 can be swiveled and pivotedas indicated by the arrows.

As shown in FIG. 5 the holonomic platform 110 may include three rollerassemblies 120 that are mounted to a base plate 121. The rollerassemblies 120 are typically equally spaced about the platform 110 andallow for movement in any direction, although it is to be understoodthat the assemblies may not be equally spaced.

The robot housing 112 may include a bumper 122. The bumper 122 may becoupled to optical position sensors 123 that detect when the bumper 122has engaged an object. After engagement with the object the robot candetermine the direction of contact and prevent further movement into theobject.

FIG. 6 shows an embodiment of a roller assembly 120. Each assembly 120may include a drive ball 124 that is driven by a pair of transmissionrollers 126. The assembly 120 may include a retainer ring 128 and aplurality of bushings 130 that captures and allows the ball 124 torotate in an x and y direction but prevents movement in a z direction.The assembly also holds the ball under the transmission rollers 126.

The transmission rollers 126 are coupled to a motor assembly 132. Theassembly 132 corresponds to the motor 88 shown in FIG. 3. The motorassembly 132 includes an output pulley 134 attached to a motor 136. Theoutput pulley 134 is coupled to a pair of ball pulleys 138 by a drivebelt 140. The ball pulleys 138 are each attached to a transmissionbracket 142. The transmission rollers 126 are attached to thetransmission brackets 142.

Rotation of the output pulley 134 rotates the ball pulleys 138. Rotationof the ball pulleys 138 causes the transmission rollers 126 to rotateand spin the ball 124 through frictional forces. Spinning the ball 124will move the robot 12. The transmission rollers 126 are constructed toalways be in contact with the drive ball 124. The brackets 142 allow thetransmission rollers 126 to freely spin and allow orthogonal directionalpassive movement of 124 when one of the other roller assemblies 120 isdriving and moving the robot 12.

As shown in FIG. 7, the pedestal assembly 114 may include a motor 150that is coupled to a gear 152 by a belt 154. The gear 152 is attached toa shaft 156. The shaft 156 is attached to an arm 158 that is coupled tothe camera 38 and monitor 40 by a bracket 160. Activation of the motor150 rotates the gear 152 and sleeve 156, and causes the camera 38 andmonitor 40 to swivel (see also FIG. 4) as indicated by the arrows 4.

As shown in FIG. 8, the assembly 114 may further include a tilt motor162 within the arm 158 that can cause the monitor 40 and camera 38 topivot as indicated by the arrows 5. The tilt motor 162 may rotate a worm164 that rotates a worm gear 166. The pin 168 is rigidly attached toboth the worm gear 166 and the bracket 160 so that rotation of the gear166 pivots the camera 38 and the monitor 40. The camera 38 may alsoinclude a zoom feature to provide yet another degree of freedom for theoperator.

In operation, the robot 12 may be placed in a home or a facility whereone or more patients are to be monitored and/or assisted. The facilitymay be a hospital or a residential care facility. By way of example, therobot 12 may be placed in a home where a health care provider maymonitor and/or assist the patient. Likewise, a friend or family membermay communicate with the patient. The cameras and monitors at both therobot and remote control stations allow for teleconferencing between thepatient and the person at the remote station(s).

The robot 12 can be maneuvered through the home or facility bymanipulating the input device 32 at a remote station 16.

FIG. 9 shows a plurality of remote stations 16A-C that can access arobot 12 through a network 18. One of the remote stations 12B can bedesignated a master station which contains an arbitrator 250. The remotestations 16 may be configured so that all messages, commands, etc.provided to the robot 12 are initially routed to the master remotestation 16B. Each message packet may include a priority field thatcontains the priority number of the station 16A, 16B or 16C sending themessage. The arbitrator 250 determines which station has priority andthen forwards the message from that station 16A, 16B or 16C to the robot12. The arbitrator 250 may also send a call back message to the otherremote station(s) stating that the station(s) with lower priority doesnot have access to the robot 12. The arbitrator 250 can cut-off accessto the robot from one station and provide access to another station witha higher priority number.

Alternatively, a remote station may route a message, command, etc. tothe robot 12 which then forwards a message, command, etc. to thearbitrator 250 to determine whether the station should have access. Thearbitrator 250 can then provide a reply message either granting ordenying access to the robot.

FIG. 10 shows a flowchart describing a process for access the robot 12.A remote station 16A, 16B or 16C may generate a request message toaccess the robot in block 300. The message may include the prioritynumber of the remote station. The arbitrator 250 determines whether therequest includes a priority number higher than any existing prioritynumber in decision block 302. If a remote station has the same prioritynumber the station first in time maintains access to the robot.

If the request included the highest priority number the arbitratorallows access to the robot in block 304. If the request does not containthe highest priority number, then arbitrator 250 sends a call-backmessage in block 306. To establish priority, the users may be dividedinto classes that include the robot itself, a local user, a caregiver, adoctor, a family member, or a service provider. The robot 12 mayoverride input commands that conflict with robot operation. For example,if the robot runs into a wall, the system may ignore all additionalcommands to continue in the direction of the wall. A local user is aperson who is physically present with the robot. The robot could have aninput device that allows local operation. For example, the robot mayincorporate a voice recognition system that receives and interpretsaudible commands.

A caregiver is someone who remotely monitors the patient. A doctor is amedical professional who can remotely control the robot and also accessmedical files contained in the robot memory. The family and serviceusers remotely access the robot. The service user may service the systemsuch as by upgrading software, or setting operational parameters.

Message packets may be transmitted between a robot 12 and a remotestation 16. The packets provide commands and feedback. Each packet mayhave multiple fields. By way of example, a packet may include an IDfield a forward speed field, an angular speed field, a stop field, abumper field, a sensor range field, a configuration field, a text fieldand a debug field.

The identification of remote users can be set in an ID field of theinformation that is transmitted from the remote control station 16 tothe robot 12. For example, a user may enter a user ID into a setup tablein the application software run by the remote control station 16. Theuser ID is then sent with each message transmitted to the robot.

The robot 12 may operate in one of two different modes; an exclusivemode, or a sharing mode. In the exclusive mode only one user has accesscontrol of the robot. The exclusive mode may have a priority assigned toeach type of user. By way of example, the priority may be in order oflocal, doctor, caregiver, family and then service user. In the sharingmode two or more users may share access with the robot. For example, acaregiver may have access to the robot, the caregiver may then enter thesharing mode to allow a doctor to also access the robot. Both thecaregiver and the doctor can conduct a simultaneous teleconference withthe patient.

The arbitrator may have one of four mechanisms; notification, timeouts,queue and call back. The notification mechanism may inform either apresent user or a requesting user that another user has, or wants,access to the robot. The timeout mechanism gives certain types of usersa prescribed amount of time to finish access to the robot. The queuemechanism is an orderly waiting list for access to the robot. The callback mechanism informs a user that the robot can be accessed. By way ofexample, a family user may receive an e-mail message that the robot isfree for usage. Tables 1 and 2, show how the mechanisms resolve accessrequest from the various users.

TABLE I Access Medical Command Software/Debug Set User Control RecordOverride Access Priority Robot No No Yes (1) No No Local No No Yes (2)No No Caregiver Yes Yes Yes (3) No No Doctor No Yes No No No Family NoNo No No No Service Yes No Yes Yes Yes

TABLE II Requesting User Local Caregiver Doctor Family Service CurrentLocal Not -Warn current user -Warn current user of -Warn current user of-Warn current user of User Allowed of pending user pending user pendinguser pending user -Notify requesting -Notify requesting user -Notifyrequesting user -Notify requesting user that system is that system is inuse that system is in use user that system is in use in use -Set timeout= 5 m -Set timeout = 5 m -No timeout -Set timeout -Call back -Call backCaregiver -Warn current user Not Allowed -Warn current user of -Warncurrent user of -Warn current user of of pending user. pending userpending user pending user -Notify requesting -Notify requesting user-Notify requesting user -Notify requesting user that system is thatsystem is in use that system is in use user that system is in use inuse. -Set timeout = 5 m -Set timeout = 5 m -No timeout -Release control-Queue or callback -Callback Doctor -Warn current user -Warn currentuser -Warn current user of -Notify requesting user -Warn current user ofof pending user of pending user pending user that system is in usepending user -Notify requesting -Notify requesting -Notify requestinguser -No timeout -Notify requesting user user that system is user thatsystem is that system is in use -Queue or callback that system is in usein use in use -No timeout -No timeout -Release control -Set timeout = 5m -Callback -Callback Family -Warn current user -Notify requesting -Warncurrent user of -Warn current user of -Warn current user of of pendinguser user that system is pending user pending user pending user -Notifyrequesting in use Notify requesting user -Notify requesting user -Notifyrequesting user user that system is -No timeout that system is in usethat system is in use that system is in use in use -Put in queue or Settimeout = 1 m Set timeout = 5 m -No timeout -Release Control callbackQueue or callback -Callback Service -Warn current user -Notifyrequesting -Warn current user of -Warn current user of Not Allowed ofpending user user that system is request pending user -Notify requestingin use -Notify requesting user -Notify requesting user user that systemis -No timeout that system is in use that system is in use in use-Callback -No timeout -No timeout -No timeout -Callback Queue orcallback

The information transmitted between the station 16 and the robot 12 maybe encrypted. Additionally, the user may have to enter a password toenter the system 10. A selected robot is then given an electronic key bythe station 16. The robot 12 validates the key and returns another keyto the station 16. The keys are used to encrypt information transmittedin the session.

FIG. 11 shows a robot head 350 that can both pivot and spin the camera38 and the monitor 40. The robot head 350 can be similar to the robot 12but without the platform 110. The robot head 350 may have the samemechanisms and parts to both pivot the camera 38 and monitor 40 aboutthe pivot axis 4, and spin the camera 38 and monitor 40 about the spinaxis 5. The pivot axis may intersect the spin axis. Having a robot head350 that both pivots and spins provides a wide viewing area. The robothead 350 may be in the system either with or instead of the mobile robot12.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat this invention not be limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those ordinarily skilled in the art.

For example, although the arbitrator is described and shown as being inone of the remote stations, the arbitrator could be within a server,robot or any device, that is connected to the network and incommunication with both the remote stations and the robot.

1. A robot system, comprising: a mobile robot that has a camera and amonitor; a first remote station that can access said mobile robot; and,a second remote station that includes an arbitrator that can controlaccess to said mobile robot by said first and second remote stations. 2.The system of claim 1, wherein said arbitrator includes a notificationmechanism.
 3. The system of claim 1, wherein said arbitrator includes atimeout mechanism.
 4. The system of claim 1, wherein said arbitratorincludes a queue mechanism.
 5. The system of claim 1, wherein saidarbitrator includes a call back mechanism.
 6. The system of claim 1,wherein said second remote station can access said mobile robot, andsaid first and second remote stations each have a priority and saidarbitrator provides robot access to said remote station with a highestpriority.
 7. The system of claim 6, wherein said remote stations may begiven priority as a local user, a doctor, a caregiver, a family member,a service user or another mobile robot.
 8. The system of claim 1,wherein said mobile robot operates in either an exclusive mode or asharing mode.
 9. The system of claim 1, wherein said first remotestation transmits a communication for said mobile robot that isinitially transmitted to said second remote station.
 10. The system ofclaim 1, wherein said first remote station sends a communication forsaid mobile robot that is initially transmitted to said mobile robot.11-20. (canceled)
 21. A method for controlling access to a remotecontrolled robot, comprising: transmitting a request to access a mobilerobot from a first remote station; determining whether the first remotestation should have access to the mobile robot at a second remotestation; allowing access to the mobile robot; and, transmitting videoimages between the robot and the first remote station.
 22. The method ofclaim 21, further comprising requesting access to the mobile robot fromthe second remote station and notifying the first remote station of therequest.
 23. The method of claim 22, wherein the second remote stationcreates a time interval in which the first remote station mustrelinquish access to the mobile robot.
 24. The method of claim 22,wherein the request from the second remote station is placed in awaiting list queue.
 25. The method of claim 21, further comprisingtransmitting a call back message from the second remote station to thefirst remote station to indicate the granting of access to the mobilerobot.
 26. The method of claim 21, wherein the access request includes apriority that is evaluated by the second remote station to determineaccess to the mobile robot.
 27. The method of claim 26, wherein theremote stations may be given priority as a local user, a doctor, acaregiver, a family member, a service user or another mobile robot. 28.The method of claim 25, wherein the mobile robot operates in either anexclusive mode or a sharing mode.
 29. The method of claim 25, whereinthe access request is initially transmitted to the second remotestation.
 30. The method of claim 25, wherein the access request isinitially transmitted to the mobile robot. 31-60. (canceled)